US investigators have opened an inquiry after an Alaska AirlinesBoeing 737 incorrectly departed from the wrong runway at Seattle-Tacoma International airport.

The incident involving flight AS61 to Juneau occurred three days ago when the aircraft was assigned runway 34C for departure.

Instead the jet took off from the parallel runway 34R which is situated halfway between Seattle-Tacoma’s terminal complex and runway 34C. With a length of 11,900ft (3,627m), runway 34R is the longer of the two by about 25%.

“There were no injuries or damage and the flight continued uneventfully to Juneau,” says the US National Transportation Safety Board. The aircraft was said to be carrying 67 passengers and crew.

The NTSB has not given weather data at the time of the incident, around 08:40 on 30 October.

Local media cite the US Federal Aviation Administration as stating that the crew read back the correct runway assignment to air traffic control.

Investigation of the incorrect departure comes two months after the fatal loss of a ComairBombardier CRJ100 which crashed after departing from the wrong runway at Lexington’s Blue Grass Airport in Kentucky